Automatic safety brake



A. KHVIBLE.

AUTOMATIC SAFETY BRAKE.

APPLICATION FILED AuG.22. 1921.

Patented 00%.

prevent the operation of the transmission driven member 2. A springsuitably 70 v tion is shown in the ccompanying .drawjournaled inbrackets 12 mounted on the W at to effect the aforesaid partial rotationof and extends through an opening 21 in the 100 to a brake member 1, aconnected rotatable 2 and thereby automatically creates a cer- 10% uponthe desired part of the apparatus with ditions. The amount of tension onthe belt 110 patented-Uetdl, 1922 7 i 'l NITED STATES PATENT OFFICE.

aus'rm mMBLn, or waosan; Wisconsin, assrenoa 'ro tranarnon anaemic mm.00., or WAUSAU, wrsconsm, a conrona'rron or wrsoonsm.

AUTOMATIC earner snake.

Application filed August 2a, 1921. serial-no. 494,254.

To al'lwhom it may oon'cem: which it is to be operated. In the drawings,

'Be' it known that I, AUSTIN KIMBLE, a the brake mechanism is shown inconjunccitizen of-the United States of America, and tion with .arotatable element 5 such as a a resident of Wausau, county of Marathon,brake drum or wheel of an elevator hoisting 5 and State of Wisconsin,have invented cerapparatus. v

tain new and usefullmprovements in Auto- The brake member 1 is in theform of an matic Safety Brakes, of which the followarm pivotally mountedupon a bracket 6 ing is a specification. secured to the base 4. The,outer end, of the The main ob ects of this invention are to arm isprovided with 'a brake shoe 7 which 10 provide an improved form of brakemecha- 1s adapted to contact with the surface of nism for use w1th powertransmlssion apthe drum or rotatableelement 5. The in-' paratus which isintermittently started and ner end of the arm has a gear segment 8stopped; to provide improved means for formed thereon which meshes witha gear normally urging the brake into positlon to or pinion 9 connectedto rotate with the apparatus; to provide an improved mechaarranged uponthe base 4 abuts against the nism controlled by the cutting in and offof outer end of the arm 1 and normally urges power to the transmissionapparatus for the shoe 7 into its effective or brakingposiautomatic'ally retracting and releasing the tion. The size and thestrength of this 20- brake mechanism; and to provide an imspring is suchas will provide the desired 7 proved automatic safetypbrake mechanismpressure of the brake shoe 7 againstthe roof this kind which isparticularly adapted tatable element 5. for use with electric elevatorapparatus. The driven member 2 is herein shown in An illustrativeembodiment of this inventhe form of a pulley secured to a shaft 11 in s,in whichbase 4. The shaft 11 has the gear or pinigure 1 is a sideelevation of an imion 9 keyed .thereto. proved automatic safety brakemechanism The driving member 3 is herein shown constructed inaccordancewith this invenin the form of a motor arranged upon'a 30 tion. I support13 which is ivotally mounted at Fi ure 2 is an enlarged-side elevationof 14 upon the base 4. 4T pulley 15 is secured one orm of pulleyconstructed to dissipate to the motor shaft and is connected by a heatcreated by a slipping belt, such a pulley belt 16 to the driven member2. being essential to the practical use of a brake In order to secure auniform tension upon 35 mechanism of this kind. l the belt 16, anddeliver a constant torque 9 An automatic safety brake mechanism to thedriven member 2, belt-tensioning. constructed in accordance with thisinvenmeans are provided for urging the pivotally tion involves the useof a brake member re-. mounted motor 3 away from the driven tractablefrom its normal braking position member 2. These tensioning means, as 40by the partial rotation of a rotatable or herein shown, comprise aspring 17 embracdriven member connected to a driving meming a rod 18 andinterposed between the her by a belt which is tensioned by suitablesupport 13 and a threaded nut 19 mounted means so that the belt willdeliver a conon the outer end of the rod 18. The rod stant torque to thedriven member suflicient 18 is pivotally mounted at 20 to the base 4:

said driven member and its retention in support 13. The spring 17bearlng between such position as long as the driving memthe nut 19 andthe support 13 normally ber continues to operate. urges the axis of thedriving member 3 In the specific embodiment herein shown, away from theaxis of thedrlven member or driven member 2, and a driving member taintension upon the belt 16 which tension 3 are arranged upon a suitablebase 4 so is always the same regardless of the weather as to provide acomplete unitary structure conditions to which the belt 'may besubcapable of being set into position to act jected or irregularities inoperatmg conthrough the gear 9 and segment 8 to arm 1 causing it toswing down against the spring 10 a suflicient distance to free therotatable element 5.

The relative slipping of the belt caused'by the continuous rotation ofthe pulley 15 heats the belt and the pulley and unless the heat isdissipated, would cause injury to the belt. Accordingly it is essentialto the practical operation of a device of this kind to make use of someform of pulley which can.

be cooled. One form of pulley particularly suited for this purpose is aventilated pulley such as that shown in U. S. Patent 1,372,700, grantedMarch 29, 1921. This form of pulley is more clearly illustrated inFigure 2 the same having an axially disposed annular passage 22 betweenthe hub 23 and the rim 24 communicating at its inner end with a radiallydisposed annular passage formed between the flanges 25 and 26. Vanes 27are arranged between the flanges 25 and 26 so as to form a fan which,when the pulley is rotating, draws air in through the passage 22 anddischarges it centrifugally outward from between the flanges 25 and 26.

A brake mechanism constructed in accordance with this invention isparticularly suitable for use with electric elevator apparatus. Whenthus used, the motor or driving member 3 would be connected with thecontroller in the car in such a manner that upon the shifting of thecontroller the circuit to the motor 3 will be closed causing the motorto operate instantly and retract the brake 1 as hasalready beenexplained. So long as the elevator is in motion the motor 3 continues tooperate and hold the brake member 1 retracted. However, as soon as thecontroller is shifted to out off the current the motor will cease toexert a pull on the driven member 2 whereupon the spring 10 will act tothrow the brake shoe 7 into position against the rotating element 5 withwhich it is arranged to coact.

Although but one specific embodiment of this invention has been hereinshown and described, it will be understood that numerous details of theconstruction shown may be altered or omitted without departing from thespirit of this invention as defined by the following claims.

' I claim:

1. In a device of the class described, the

combination of a shiftable brake member, a

rotatable member, mechanism connecting said brake member to be actuatedby said rotatable member, a driving member, a belt connecting saiddriving member with said rotatable member, and means for creating atension on said belt sufficient to cause the rotation of said drivingmember to shift and hold said brake member in its retracted position.

2. In a device of the class described, the combination of a shiftablebrake member, a rotatable member, mechanism connecting said brake memberto be actuated by said rotatablemember, means normally urging said brakemember into its braking position, a driving member, a belt connectingsaid driving member with said rotatable member, and means for creating atension on said belt sufiicient to cause the rotation of said drivingmember to shift and hold said brake member against the action of saidmeans,

3. In a device of the class described, the combination of a pivotallymounted member, a brake shoe carried on onei'end ofksaid member, aspring normally urging said member to move said shoe into its brakingposition, a rotatable member, gearing connecting said rotatable memberwith said pivotally mounted member, a driving member, a belt connectingsaid driving member with said rotatable member, and means for creating a.tension on said belt suflicient to cause said driving member to actuatesaid rota-- table member and through said gearing shift said pivotallymounted member and hold same inits retracted position.

4. 'In a device of the class described, the combination of a pivotallymounted member, a brake shoe carried on one end of said member, a springnormally urging said member to move said shoe into its braking position,a rotatable member, gearing connecting said rotatable member with saidpivotally mounted member, a driving member, a belt connecting saiddriving member with said rotatable member, means for creating a tensionon said belt sufiicient to cause said driving member to actuate saidrotatable member and through said gearing shift said pivotally mountedmember and hold same in its retracted position, and other means foradjusting said tension means so as to regulate the retraction of saidbrakeshoe member.

5. In a device of the class described, the combination of a base, amember pivotally -mounted on said base and provided with a brake shoe atone end and a gear segment at the other, a spring normally urging saidmember to locate said brake shoe in its funcon said base and having agear meshing with said gear segment, a driving member jour- I naled on asupport pivotally mounted on 'said base, a belt connecting said drivingmember with said driven member, and a spring acting between said baseand said support normally urging said driving member to automaticallycreate a. uniform tension on said belt whereby said driving member willactuate said driven member toretract said brake-shoe member and hold thesame in its retracted position so long as said driving member isrotating.

6. In a device of the class described. the combination of a'shiftablebrake member, a rotatable member, mechanism connecting said brake memberto be actuated by said rotatable member, an electric motor. a beltconnecting said motor with said rotatable member. and means for creatinga tension on said belt sufficient to cause the rotation of said motor toshift and hold said brake member in its retracted position.

7. In a device of the class described, the combination of a base, amember pivotally mounted on said base and provided with a brake shoe atone end and a gear segment at the other, a spring normally urging saidmember to locate said brake shoe in its functioning position. a'drivenmember journaled on said base and having a gear meshing with said gearsegment, an electric motor journaled on a support pivotally mounted onsaid base, a belt connecting said motor with sa id drivenmembeig'aspring acting between said support and said base and normallyurging said motor to automatically create a uniform tension on said beltwhereby said driven member is actuated to retract said brake shoe memberand to hold same in its retracted position so long as said motor isrotating.

Signed at (hicago this 17th day of August, 1921.

AUSTIN KIMBLE.

